For traditional semiconductor manufacturing processes, after forming a contact hole in the silicon substrate, the process further includes a step of performing a cleaning process to remove residues in the contact hole; and then forming a contact plug in the cleaned contact hole. However, due to the miniaturization of chip, a higher aspect ratio of the contact plug is required to reduce the resistance of a metal wire. Increasing the aspect ratio of the contact plug means that an opening of the contact hole becomes smaller or a depth of the contact hole becomes deeper. Using the traditional cleaning process to remove the residues in the contact hole having a deeper depth may cause incomplete cleaning issues and then reducing a reliability of components.
In view of the aforementioned reasons, there is a need to provide a new cleaning method to solve the aforementioned incomplete cleaning issues.